Butterflies can keep their proboscises clean despite sipping from pollen-dusted flowers, roadside puddles, carrion or dung. The trick: Easy-care surfaces along most of the proboscis repel water and debris. Only the tip is fluid friendly.

In butterflies such as Limenitis archippus, bowling-pin-shaped sensory structures at the tip form a brush that helps draw moisture into the sipping tube. And the tube has seams down its top and bottom that have gaps at the tip to draw in fluids, Konstantin Kornev of Clemson University in South Carolina and his colleagues report June 12 in the Journal of the Royal Society Interface.